Despite what some blogs and websites may tell you (written by someone who doesn't know). There is no option to insure locally with a full excess covered. Typically you will take an Antigua policy through any Antigua car rental company. For Antigua there is always an excess and more likely not advertised to you but buried in small print.

let's talk about the 3 options available to you to better illustrate the situation.

1. Antigua insurance- on a smaller car the excess on cover would be around $1000 that is the maximum you will pay from your credit card. You can find an excess policy online to top up this cover. For an SUV this increases to $1,500 USD.
2. Antigua insurance locally plus a top up insurance. Your Antigua policy covers you and liability then the extra separate policy covers any excess. You will initially be charged deductibles and claim them back from the top up policy after.
3. Take out an external full policy - decline the local insurance policy and sign that you do not take it. Check the policy covers Antigua and Barbuda and what it covers. You may still find there are some items that are deductible.
4. No Insurance- Not recommended and you are liable for the full amount up to the value of the car and other costs that could come down to reckless driving on your part- think liability and damage a car can do not just to itself, including in extreme cases loss of life. 

Note

Check your travel insurance to see if you have extra cover, sometimes your credit card may also provide cover. It is up to you to check the details of any policy.

The information provided here is for informational purposes only and should not be taken as legal advice.